This new science seeks to emphasize the immediate duty of man to better his conditions by availing himself of knowledge already at hand. As far as in him lies he must make application of this knowledge to secure his greatest efficiency under conditions which he can create or under such existing conditions as he may not be able wholly to control, but such as he may modify. The knowledge of the causes of disease tends only to depress the average citizen rather than to arouse him to combat it. Hope of success will urge him forward, and it is the duty of lovers of mankind.
